Question

1. what would be the net force acting on each block below? 3n 5n 5n 5n

Explanation:

Step1: Calculate net force for the first block

Forces are in opposite directions. Subtract smaller force from larger one.
$$F_{net1}=5N - 3N$$

Step2: Calculate net force for the second block

Forces are in same direction. Add the forces.
$$F_{net2}=5N+5N$$

Answer:

For the first block: $2N$ (to the right). For the second block: $10N$ (to the right).